package com.example.datastructure.unit6;

import java.util.*;
 
/**
 * @author ASUS
 */
public class Main {
   private LinkedList list = new LinkedList();
   public void push(Object v) {
      list.addFirst(v);
   }
   public Object top() {
      return list.getFirst();
   }
   public Object pop() {
      return list.removeFirst();
   }
   public static void main(String[] args) {
      Main stack = new Main();
      for (int i = 30; i < 40; i++) {
          stack.push(new Integer(i));
      }
      System.out.println(stack.top());
      System.out.println(stack.pop());
      System.out.println(stack.pop());
      System.out.println(stack.pop());
   }
}